1. Field of the Invention
This invention relates to a method of producing a modifying layer or coating surface on a passive polymeric material. More particularly, this invention relates to the production of a modifying adhering layer on a passive fluorinated or a nonfluorinated polymer surface using a fluorinated alkanoyl ester modified alkoxycellulose. The modifying cellulosic layer produced has adhesive properties to bond fluorinated surfaces to other materials. The modified cellulose layer also produces a controlled hydrophilicity on the surface of a passive polymeric material, which is useful for the printing of inks, etc. on the modified surface, and for better control of water infusion in a porous membrane. The article produced having a layer of the fluorinated ester substituted alkoxy cellulose is also considered to be part of this invention. A container and the unreacted fluorinated ester substituted alkoxy cellulose composition in a form for application of the composition to the passive polymeric material is also described.
There are many types of passive polymeric materials which have surfaces not generally wettable by water, oils, paints, inks, and the like. A polymer substrate is sufficiently hydrophobic so that it is not soluble in water and usually possesses a contact angle with water of between about 65 and 130.degree., preferably between about 65 and 110.degree.. The surface of some passive polymeric materials may be swellable or soluble in the presence of certain solvent-based inks or paints. As used herein, the term "passive polymer" or "passive polymeric material" includes poly(halocarbons), poly(halohydrocarbons), poly(alkylenes), poly(carbonates) and the like. Important commercial passive polymers include the polyhalocarbon resins, for example, polytetrafluoroethylene (TEFLON.RTM. PTFE, a DuPont Co. trademark), a copolymer of tetrafluoroethylene with tetrafluoropropylene (TEFLON.RTM. FEP, a DuPont Co. trademark), and polytrifluoromonochloroethylene (Kel-F.RTM. a 3M Co. trademark, or Flurothene.RTM., a DuPont Co. trademark); poly(halohydrocarbons, such as poly(vinyl fluoride) (TEDLAR.RTM., a DuPont Co. trademark), polyvinylchloride and the like. Other polymers having generally difficultly wettable (or passive) surfaces also include the poly(alkylenes), such as polyethylene (all types) and polypropylene (all types), polycarbonates and the like. The process of the present invention is generally applicable to such passive or difficultly wettable polymers, but offers special advantages with the poly(halocarbons).